Collaborative Research: Enhancement of Vertical Elements for Foundation Support by Ureolytic Carbonate Precipitation

这一合作项目的目的是探索尿素分解方解石沉淀作为提高砂土和淤泥地基垂直支撑元件能力的一种实际手段的潜力。增强基础支撑的垂直元素有望成为生物诱导碳酸盐沉淀在岩土工程中的第一个实际应用。这项工作的一个关键内容是探索使用农业来源的尿素酶作为方解石沉淀的催化剂，而不是迄今报道的所有方解石沉淀研究中使用的微生物来源的尿素酶。加强垂直基础支撑要素所需的改良区范围有限，缓解了因碳酸盐沉淀引起的土壤质量稳定问题。使用农业衍生的尿素酶可以进一步缓解质量稳定中遇到的一些问题，并将可以通过诱导碳酸盐沉淀稳定的土壤范围扩大到淤泥大小的颗粒范围。这个项目的主要更广泛的影响是与生物介导式地基改良的实际应用的发展有关。开发这项技术的实际应用(生物介质碳酸盐沉淀)是一项潜在的变革性成就，加速了生物地球化学地基改良技术的发展，并推动了生物地质工程这一新兴领域的进一步创新发展。将生物介体碳酸盐沉淀的适用性扩大到粉砂大小的颗粒范围内，本身也将对广泛的岩土工程领域和新兴的生物岩土工程分支学科产生广泛的影响。该项目还将通过支持研究生研究助理，特别是通过培训和教育具有生物岩土工程技术和程序方面知识和能力的新研究人员，为岩土专业人员的培训和教育作出贡献，而这些技术和程序通常不在传统的岩土研究中使用。

The objective of this collaborative project is to explore the potential of ureolytic calcite precipitation as a practical means of improving the capacity of vertical support elements for foundations in sands and silts. Enhancement of vertical elements for foundation support holds promise as the first practical application of biologically induced carbonate precipitation in geotechnical engineering. A key element of the work is exploring the use of agriculturally-derived urease enzyme as the catalyst for calcite precipitation rather than microbially-derived urease employed in all calcite precipitation studies reported to date. The limited extent of the improvement zone required to enhance vertical foundation support elements mitigates problems associated with mass stabilization of soil by induced carbonate precipitation. The use of agriculturally-derived urease can further mitigate some of the problems encountered in mass stabilization and extend the range of soils that can be stabilized by induced carbonate precipitation into the silt-sized particle range. The primary broader impact of this project is associated with the development of a practical application of bio-mediated ground improvement. Developing a practical application for this technology (bio-mediated carbonate precipitation) is a potentially transformative accomplishment, accelerating the development of biogeochemical ground improvement techniques and motivating further innovative developments in the emerging field of biogeotechnical engineering. Extending the applicability of bio-mediated carbonate precipitation into the silt-sized particle range would also have, in and of itself, a broad impact on both the broad field of geotechnical engineering and the emerging sub-discipline of biogeotechnical engineering. The project will also make contributions to training and education of geotechnical professional through support of graduate student research assistants and, in particular, through training and education of new researchers knowledgeable and competent in the techniques and procedures employed in biogeotechnical engineering that are not usually employed in traditional geotechnical research.